RU2712563C2 - Heat exchanger with fin wave control - Google Patents

Abstract

FIELD: heat exchange.SUBSTANCE: plate-type fin heat exchanger comprises a plurality of ribbed cold rows configured to conduct a first fluid, and a plurality of ribbed warm rows configured to conduct a second fluid. Ribbed warm rows contain inlet side and outlet side. First section of ribs of at least one ribbed warm row of multiple ribbed warm rows contains multiple combined lifts and recesses forming a wave configuration for each rib from the first section of ribs. Upstream front edge of the first section of ribs is located at the point of the wave configuration, which represents at least one of the ascents and recesses.EFFECT: compromising the structural integrity of the heat exchanger and its ability to provide the required cooling performance.9 cl, 7 dwg

Description

State of the art

[0001] An object of the invention described herein relates generally to heat exchangers and, in particular, to a wave fin structure for heat exchangers.

[0002] A typical aviation plate fin heat exchanger comprises a series of brazed, thermally interconnected sections or rows of air flow. Hot air and cold air are forced to pass through alternating rows for heat transfer. In a gas turbine air conditioning system, hot air enters from the air intake from the engine and passes through the intake rows. Cold air is outside air and passes through the ranks of the supercharger system. These successive rows of the supercharging system and the intake are connected together along a heat-conducting means called the separation plate, and through the separating plates, heat from the intake rows enters the air stream of the supercharging system.

[0003] The rows of the supercharging system and the intake are similar, and each of them contains a plurality of cooling fins and frames or locking elements that are located on the separation plates to define each row. Frames or locking elements are placed along the ends of the rows to support the ends of the separation plates. In addition to supporting the ends of the separation plates, these locking elements cover each row, except where the air intake and exhaust systems are located. At the air inlet and air outlets, the ribs provide support for the separation plates.

[0004] For the manufacture of a heat exchanger, the rows of the supercharging system and the intake are stacked alternately on top of each other, and then placed in a vacuum soldering furnace. During the soldering process, the stacking of the rows is compressed in such a way as to join the rows together. The adhesion is completed when the ribs are soldered to the dividing plates and the edges of these plates are equally soldered along the locking elements. The air flows of the intake and the supercharging system come from the corresponding manifold pipes, which are subsequently welded to the shut-off elements.

[0005] Due to their size, such heat exchangers can be subjected to significant thermal stresses when they are heated and cooled. These loads can occur when the intake air flow starts and stops. During these heating and cooling cycles of the heat exchanger, the core expands and contracts. Over time, high thermal stresses can destroy the ribs, thus leading to cracks, which can lead to deterioration of the core sections. This can cause a violation of the structural integrity of the heat exchanger and its ability to provide the required cooling performance.

SUMMARY OF THE INVENTION

[0006] In one aspect, a plate fin heat exchanger is provided. The plate fin heat exchanger comprises a plurality of finned cold rows configured to conduct the first fluid, and a plurality of finned warm rows configured to conduct the second fluid. The ribbed warm rows contain an inlet side and an outlet side. The first portion of the ribs of at least one ribbed warm row of a plurality of plate-shaped warm rows contains a plurality of combined ups and downs defining a wave configuration for each rib from the first portion of the ribs. The upstream leading edge of the first portion of the ribs begins at the location of the wave configuration, which is at least one of the ups and downs.

[0007] In addition to one or more of the features described above, or as an alternative, further embodiments of the invention may include: wherein the plurality of plate-shaped warm rows further includes a second portion of ribs located on the inlet side adjacent to the upstream front the edge of the first portion of the ribs, while the ribs from the second portion of the ribs have a greater thickness than the ribs from the first portion of the ribs; a groove is formed in the leading edge of at least one rib from the second portion of the ribs; and / or wherein the ribs from the second portion of the ribs are two to four times thicker than the ribs from the first portion of the ribs.

[0008] In another aspect, a dual core heat exchanger is provided. The dual core heat exchanger comprises a first core and a second core, fluidly separated from the first core. The first core comprises a first plurality of ribbed cold rows configured to conduct a first fluid, a first plurality of ribbed warm rows configured to conduct a second fluid, a first plurality of ribbed warm rows having an inlet side and an exhaust side. At least the first portion of the ribs of each ribbed warm row from the first set of ribbed warm rows contains a plurality of combined rises and troughs defining a wave configuration for each rib from the first portion of the ribs. The upstream leading edge of the first portion of the ribs begins at the location of the wave configuration, which is at least one of the rises and depressions. The second core comprises a second plurality of ribbed cold rows configured to conduct the first fluid, and a second plurality of ribbed warm rows configured to conduct the third fluid. The second set of ribbed warm rows includes an intake side and an exhaust side.

[0009] In addition to one or more of the features described above or as an alternative, further embodiments of the invention may include: wherein the first core further comprises a protective rib located on the inlet side of each of the finned warm rows from the first plurality of finned warm rows, this protective rib has a greater thickness of the ribs than the ribs of the first ribbed warm rows; a second protective rib located on the inlet side of each of the ribbed warm rows from the second set of ribbed warm rows, the second protective rib having a greater thickness than the ribs of the second ribbed warm rows, with at least a second portion of the ribs of each ribbed warm row from the second the set of ribbed warm rows contains a lot of combined rises and troughs that determine the wave configuration for each rib from the second section of the ribs, while the upstream leading edge of the second o the area of the ribs begins at the place of the wave configuration, which represents at least one of the rises and depressions; a groove formed in the leading edge of the protective rib; while the protective rib is two to four times thicker than the ribs of the first set of ribbed warm rows; and / or a first inlet manifold fluidly coupled to the inlet side of the first plurality of finned warm rows, the first inlet manifold configured to supply sampled air from the engine to the first plurality of ribbed warm rows, an incoming air manifold connected to the inlet of the first plurality ribbed cold rows, wherein the incoming air manifold pipe is configured to supply incoming air to the first plurality of ribbed cold rows, and the second inlet knoy manifold fluidly coupled with the intake side of the second plurality of rows of finned warm, the second inlet manifold configured to supply compressed air from the compressor to the second plurality of rows of finned warm.

[0010] In yet another aspect, a method for manufacturing a heat exchanger is provided. This method includes providing a plurality of ribbed cold rows and providing a plurality of ribbed warm rows containing an inlet side and an exhaust side, wherein the first portion of the ribs of each ribbed warm row contains a plurality of combined lifts and troughs defining a wave configuration for each rib from the first portion of the ribs. This method further includes trimming along the combined rises and troughs of adjacent ribs from the first portion of ribs to form an upstream leading edge of the first portion of ribs starting at the location of the wave configuration, which is at least one of the lifts and troughs, and joining a plurality of cold ribbed rows and many ribbed warm rows.

[0011] In addition to one or more of the features described above, or as an alternative, further embodiments of the invention may include: providing a plurality of fins having a greater thickness than the fins of the ribs of the fin warm rows, orienting the fins of the plurality of fins on the inlet side of the ribbed warm rows of the plurality of ribbed warm rows, and wherein the joining step includes connecting the plurality of ribbed cold rows, the plurality of ribbed warm rows and the plurality of protective EP; the formation of a groove in the leading edge of at least one protective rib of the plurality of protective ribs; wherein the gutter is formed using an electric spark processing process; and / or in this case, the trimming step along the combined elevations and troughs of the wave configuration is performed using the process of electric spark processing.

[0012] These and other advantages, as well as features, will become more apparent from the following description in combination with drawings.

A brief description of the graphic materials

[0013] The subject matter of the invention, which is regarded as an invention, is particularly indicated and clearly stated in the claims in the concluding part of this description. The above and other features, as well as the advantages of this invention, are obvious from the following detailed description in combination with the accompanying graphic materials, in which:

[0014] FIG. 1 is a perspective view of a typical heat exchanger;

[0015] FIG. 2 is a perspective view of the heat exchanger illustrated in FIG. 1, with typical manifold pipes;

[0016] FIG. 3 is a cross-sectional view of the heat exchanger illustrated in FIG. 1, along the line 3-3;

[0017] FIG. 4 is a cross-sectional view of a typical protective fin of a heat exchanger intake, illustrated in FIG. 3 and shown along lines 4-4;

[0018] FIG. 5 is a cross-sectional view of an alternative embodiment of the heat exchanger illustrated in FIG. 3;

[0019] FIG. 6 is an enlarged view of the heat exchanger illustrated in FIG. 5 and shown in section 6; and

[0020] FIG. 7 is an enlarged view of the fins of the heat exchanger illustrated in FIG. 5 and 6.

[0021] A detailed description sets forth embodiments of the present invention in conjunction with advantages and features as an example with reference to graphic materials.

Detailed Disclosure of Invention

[0022] FIG. 1 and 2 illustrate a typical aviation heat exchanger 10. In a typical embodiment, the heat exchanger 10 is a high-temperature aluminum heat exchanger with two cores for an air generation unit in an airplane. However, the features described herein can be applied to any suitable heat exchanger design.

[0023] The heat exchanger 10 typically comprises a primary core 12 and a secondary core 14. Each of the cores 12, 14 comprises an intake side of sampled air 16, a side of exhaust air 18, an intake side of air 20 and a side of exhaust 22. with reference to FIG. 2, hot exhaust air from an engine (not shown) enters the core 12 from the primary intake manifold 24 and exits through the primary exhaust manifold 26. Similarly, hot air from the exhaust port of the compressor enters the secondary core 14 from the secondary intake manifold 28 and exits through secondary exhaust manifold 30. Incoming air passes from the inlet 20 to the outlet 22 through the primary core 12 and the secondary core 14 to cool both hot sampled air and hot air from the compressor. The incoming air may be supplied to the inlet side 20 by means of a manifold or flow control device (not shown) and removed through the exhaust side 22 by means of a manifold or flow control device (not shown).

[0024] The heat exchanger 10 comprises a plurality of rows defined by dividing plates 32 and cooling fins 34 which are located between the dividing plates 32. Cold or free-flowing air enters through the inlet side 20 in the direction indicated by arrow 36 and passes through a plurality of free-air rows 38. Rows of incoming air 38 are located between rows of hot air or bleed air 40 that receive hot air through the collectors 24, 28. Hot air passes through the inlets, would be formed between the locking elements intake 42 which is sealed a number of bleed air 40 in relation to the free stream direction 36. Similarly, the locking elements speed supercharging system 44 ranks the ram air sealed with respect to the flow of bleed air.

[0025] With reference to FIG. 3, the cooling fins 34 have different thicknesses in all rows 38 and / or 40. For example, the cooling fins 34 may include protective ribs of the intake 46 located upstream of the fins 48 and located downstream of the fins 50. In a typical embodiment, the thickness of the protective the ribs 46 are larger than the thickness of the upstream ribs 48, which is greater than the thickness of the downstream ribs 50. The ribs 46 are made with a greater thickness than the ribs 48, 50, due in part to the fact that the bleed air has high the temperature at the inlet side of the exhaust air 16. Due to the increased thickness, the protective ribs 46 are more able to withstand high thermal loads, such as the expansion and contraction of adjacent locking elements 42, as well as the expansion and contraction of individual protective ribs 46. Accordingly, the thermocyclic durability is significantly increased protective ribs 46.

[0026] In addition, in an exemplary embodiment of the invention, the upstream fins 48 are made with a greater thickness than the downstream fins 50 due in part to the fact that the bleed air has a reduced temperature when passing from the inlet side 16 to the outlet side 18. Thus, the thermal load on the ribs 34 decreases as the ribs move away from the inlet side 16 to the outlet side 18, so that the thickness of the ribs 34 can decrease downstream. Alternatively, the upstream and downstream fins 48, 50 may have the same thickness and the protective fins 46 may be thicker. Protective ribs 46 may be used in the primary core 12 and / or the secondary core 14. In addition, in the exemplary embodiment of the invention illustrated in FIG. 3, the protective ribs 46 are straight or flat, and the ribs 48, 50 are wavy, corrugated or offset. Alternatively, the protective ribs 46 may be wavy, and the ribs 48, 50 may be straight.

[0027] In one embodiment, the protective ribs 46 are 40% to 60% thicker than the upstream ribs 48 and two to four times thicker than the upstream ribs 50. In another embodiment, the protective ribs 46 about 40% to 60% thicker downstream fins and about two to four times thicker downstream fins 50. In one embodiment, the protective fins 46 are 55% thicker than the upstream fins 48 and three times thicker downstream ribs 50. In another embodiment, the protective ribs 46 are approximately 55% thicker than the upstream ribs 48 and about three times thicker than the lower ribs 50.

[0028] In one embodiment, the thickness of the protective ribs 46 is from 0.2032 mm (0.008 inches) to 0.254 mm (0.01 inches). In another embodiment, the thickness of the protective ribs 46 is from about 0.2032 mm (0.008 inches) to about 0.254 mm (0.01 inches). In yet another embodiment, the thickness of the protective ribs 46 is 0.2286 mm (0.009 inches) or about 0.2286 mm (0.009 inches). In one embodiment, the thickness of the upstream ribs 48 is from 0.1016 mm (0.004 inches) to 0.1524 mm (0.006 inches). In another embodiment, the thickness of the upstream ribs 48 is from about 0.1016 mm (0.004 inches) to about 0.1524 mm (0.006 inches). In yet another embodiment, the thickness of the upstream ribs 48 is 0.127 mm (0.005 inches) or about 0.127 mm (0.005 inches). In one embodiment, the thickness of the downstream ribs 50 is from 0.0508 mm (0.002 inches) to 0.1016 mm (0.004 inches). In another embodiment, the thickness of the downstream ribs 50 is from about 0.0508 mm (0.002 inches) to about 0.1016 mm (0.004 inches). In yet another embodiment, the thickness of the downstream ribs 50 is 0.0762 mm (0.003 inches) or about 0.0762 mm (0.003 inches). However, the protective ribs 46 located upstream of the ribs 48 and located downstream of the ribs 50 can have any thickness that ensures the functioning of the ribs as described in this document.

[0029] As illustrated in FIG. 4, the protective ribs 46 may include a groove 52 formed in the leading edge 54 to facilitate matching thermal expansion of an adjacent structure (e.g., locking elements 42). The groove 52 allows the leading edge of the protective rib 54 to expand and contract during rapid thermal changes on the inlet side of the primary heat exchanger 16 of the primary core 12 and / or secondary core 14. In a typical embodiment, the groove 52 has a rounded end 56. However, the end of the groove 56 may have any shape that allows the protective rib 46 to function as described in this document. In an exemplary embodiment of the invention, a groove 52 is formed at the leading edge 54 by electrospark processing. However, the chute 52 may be formed by any suitable process.

[0030] In one embodiment, the depth of the groove 58 is from 20% to 40% of the length of the rib 60. In another embodiment, the depth of the groove 58 is from about 20% to about 40% of the length of the rib 60. In another embodiment, the depth the groove 58 is 30% or about 30% of the length of the rib 60. In one embodiment, the depth of the groove 58 is from 3.81 mm (0.15 in) to 8.89 mm (0.35 in). In another embodiment, the depth of trough 58 is from about 3.81 mm (0.15 in) to about 8.89 mm (0.35 in). In yet another embodiment, the depth of the gutter 58 is 6.35 mm (0.25 inches) or about 6.35 mm (0.25 inches). In one embodiment of the invention, the length of the rib 60 is from 20.32 mm (0.8 inches) to 25.4 mm (1.0 inches). In another embodiment, the fin length 60 is from about 20.32 mm (0.8 inches) to about 25.4 mm (1.0 inches). In yet another embodiment of the invention, the length of the rib 60 is 22.86 mm (0.9 inches) or about 22.86 mm (0.9 inches).

[0031] In one embodiment, the width of the groove 62 is from 20% to 40% of the width of the ribs 64. In another embodiment, the width of the groove 62 is from about 20% to about 40% of the width of the ribs 64. In another embodiment, the width the groove is 30% or about 30% of the width of the rib 64. In one embodiment of the invention, the width of the groove 62 leaves from 1.27 mm (0.05 inches) to 1.778 mm (0.07 inches). In another embodiment, the width of the trough 62 is from about 1.27 mm (0.05 inches) to about 1.778 mm (0.07 inches). In yet another embodiment, the width of the trough 62 is 1.524 mm (0.06 inches) or about 1.524 mm (0.06 inches). In one embodiment of the invention, the width of the rib 64 leaves from 3.81 mm (0.15 inch) to 8.89 mm (0.35 inch). In another embodiment, the width of the rib 64 is from about 3.81 mm (0.15 in) to about 8.89 mm (0.35 in). In yet another embodiment of the invention, the width of the rib 64 is 6.35 mm (0.25 inches) or about 6.35 mm (0.25 inches).

[0032] The heat exchanger 10 can be manufactured by laying dividing plates 32 with installed locking elements 42, 44 and cooling fins 34 (including protective fins 46). Then, a load is applied to the rows to compress them together, after which the assembly is placed in a vacuum oven, where it is heated to a temperature at which the separation plates 32 are soldered to the locking elements 42, 44 and ribs 34. Then, in the leading edges 54 of the protective ribs gutters 52 can be formed, for example, by electric spark treatment. After that, the collectors 24, 26, 28, 30 are attached to the heat exchanger 10.

[0033] With reference to FIG. 5, another embodiment of the heat exchanger 10 comprises cooling fins 134, and the same reference numerals indicate the same elements. In the illustrated embodiment, cooling ribs 134 include guard ribs 46 of the intake, wavy upstream ribs 148 and downstream ribs 50. Upstream ribs 148 comprise upstream leading edge 150 located close to or downstream protective ribs 46 of the intake to define a gap 149 between them. Alternatively, the cooling ribs 134 may not contain protective ribs 46, so that the upstream leading edge 150 is placed on the front edge of the heat exchanger 152 (i.e., where to position the front edge 54 of the protective rib).

[0034] With further reference to FIG. 6 and 7, each undulating upstream rib 148 comprises a plurality of ups / downs 154 that define the cycle of the rib 155 (FIG. 7). In one embodiment, the wavy ribs 148 may have a sinusoidal shape that defines each rise / depression 154. As illustrated in FIG. 7, the lifts / depressions 154 of adjacent ribs 148 are aligned, and the ribs 148 comprise an upstream leading edge 150 that forms and starts at a point located in the cycle of the rib 155 (each rib 148), which is either the lifts or the hollow 154.

[0035] In one embodiment of the invention, the upstream ribs 148 are equally cut or trimmed along the usually aligned lifts / depressions 154 using electrospark machining (ESM) to form an upstream leading edge 150. Since the leading edge 150 is formed on the rise / the cavity 154 of each rib 148, located upstream of the ribs 1448 can better withstand high thermal loads. Accordingly, the thermocyclic durability of the ribs 148 is significantly increased. For this reason, the combination of the rises / troughs 154 of the adjacent corrugated ribs 148 provides an unexpected increased fatigue life of the ribs. In one experiment, fatigue testing showed that wave control of ribs with leading edge 150, starting at the elevations / depressions 154 of each rib 148, significantly increased the number of fatigue cycles of heat exchanger 10. The inclusion of protective ribs 46 also increased the number of fatigue cycles of heat exchanger 10. Accordingly, testing confirmed that the appearance of cracks in the ribs is directly related to the position of the ribs on the leading edge 150.

[0036] In other embodiments, the trailing edge 156 of the undulating upstream ribs 148 may be trimmed along the rises / depressions 154 to further increase the fatigue life of the ribs. In addition, the downstream ribs 50 may also have a wave-like configuration and comprise an upstream leading edge 158 and / or trailing edge 160 that are formed or trimmed along the rises and troughs of the undulating ribs located downstream of the ribs 50.

[0037] The cooling fins 134 may be formed by wavy upstream fins 148. A measuring device (not shown) may be used to align the individual wavy fins 148, and the wavy fins 148 may be respectively trimmed (for example, by means of EI) to be aligned lifts / depressions 154 to form the leading edge 150. Accordingly, adjacent wavy ribs 148 are aligned at the same point of the cycle of the ribs 155 to ensure the same leading edge 150 (see Fig. 6), which increases the fatigue life of the cooling giving ribs 134. In some embodiments of the invention, the cooling ribs 134 may be provided with guard ribs 46 located upstream of the leading edge 150 to further increase the fatigue life of the cooling ribs 134. In other embodiments, the cooling ribs 134 may include ribs 156, 158 and / or 160, which are likewise trimmed along the rises / depressions of adjacent wavy ribs.

[0038] The heat exchanger 10 can be manufactured by laying dividing plates 32 with installed locking elements 42, 44 and cooling fins 134. Then, a load is applied to the rows to compress them together, after which the assembly assembly is placed in a vacuum oven, where it is heated to the temperature at which the dividing plates 32 are soldered to the locking elements 42, 44 and ribs 134. If protective ribs 46 are included, then grooves 52 can be formed in the leading edges 54 of the protective ribs, for example, using an EI process. After that, the collectors 24, 26, 28, 30 are attached to the heat exchanger 10.

[0039] Although the invention has been described in detail in connection with only a limited number of embodiments of the invention, it can be readily understood that the invention is not limited to such disclosed embodiments of the invention. On the contrary, the invention can be modified to include any number of variations, changes, replacements or equivalent devices that are not previously described, but are comparable with the essence and scope of this invention. In addition, while various embodiments of the invention have been described, it should be understood that aspects of the present invention may include only some of the described embodiments of the invention. Accordingly, this invention should be considered as limited only by the scope of the attached claims, and not the above description.

Claims (20)

1. A plate fin heat exchanger comprising: a plurality of ribbed cold rows configured to conduct the first fluid; and a plurality of ribbed warm rows configured to conduct a second fluid, the ribbed warm rows having an inlet side and an exhaust side, wherein the first portion of the ribs of at least one ribbed warm row of a plurality of ribbed warm rows contains a plurality of combined rises and troughs defining a wave configuration for each rib from the first portion of the ribs, wherein the upstream leading edge of the first portion of the ribs begins at the location of the wave configuration, which is at least one of the rises and depressions. 2. A plate-type fin heat exchanger according to claim 1, characterized in that the plurality of plate-shaped warm rows further comprises a second section of ribs located on an inlet side adjacent to an upstream leading edge of the first section of ribs, the ribs from the second section of ribs having a large thickness than the ribs from the first portion of the ribs. 3. The plate fin heat exchanger according to claim 2, further comprising a groove formed in the leading edge of at least one rib from the second portion of the ribs. 4. The plate fin heat exchanger according to claim 2, characterized in that the ribs from the second portion of the ribs are two to four times thicker than the ribs from the first portion of the ribs. 5. A method of manufacturing a heat exchanger, including: providing multiple ribbed cold rows; providing a plurality of finned warm rows having an inlet side and an exhaust side, wherein the first portion of the ribs of each ribbed warm row comprises a plurality of combined lifts and troughs forming a wave configuration for each rib from the first portion of the ribs; trimming along the combined rises and depressions of adjacent ribs from the first portion of ribs to form an upstream leading edge of the first portion of ribs, starting at the location of the wave configuration, which is at least one of the lifts and troughs; and the combination of many ribbed cold rows and many ribbed warm rows. 6. The method according to p. 5, further comprising: providing multiple protective ribs having a greater thickness of the ribs than the ribs of the ribbed warm layers; the orientation of the protective ribs of the many protective ribs on the inlet side of the ribbed warm rows of the many ribbed warm rows; and wherein the joining step includes joining a plurality of ribbed cold rows, a plurality of ribbed warm rows and a plurality of protective ribs. 7. The method according to claim 6, further comprising forming a trough in the leading edge of at least one protective rib from the plurality of protective ribs. 8. The method according to p. 7, characterized in that the trough is formed using the process of electric spark processing. 9. The method according to p. 5, characterized in that the step of cutting along the combined elevations and troughs of the wave configuration is performed using the process of electric spark processing.

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